Scroll compressor and method for assembling same

ABSTRACT

A scroll compressor having a housing composed of multiple sub-housings (12, 14, 16), comprising a motor sub-housing which is equipped with a drive motor with a stator fixed to the housing and a coaxial rotor fixed to a main shaft mounted on one side of the stator by a first main shaft bearing; a bearing sub-housing that adjoins the motor sub-housing on the side facing away from the first main shaft bearing and supports a second main shaft bearing and an orbital guide of a first scroll-type displacement device, which is eccentrically connected to the main shaft and orbits during a rotation of the main shaft and into which a second scroll-type displacement device fixed to the housing engages axially; and a housing cover which adjoins the bearing sub-housing and terminates the housing. The second scroll-type displacement device is directly connected to the bearing sub-housing.

The present invention relates to a scroll compressor having a housing composed of a plurality of housing sections, including

a motor housing section in which are configured a drive motor having a housing-fixed stator and a main shaft-fixed, coaxial rotor mounted on one side of the stator by a first main shaft bearing;

a bearing housing section, which adjoins the motor housing section on the side facing away from the first main shaft bearing and which supports a second main shaft bearing as well as an orbital guide of a first spiral displacer, which is eccentrically coupled to the main shaft and orbits in response to the rotation thereof, and into which axially engages a housing-fixed, second spiral displacer;

a housing cover which adjoins the bearing housing section and terminates the housing.

The present invention also relates to a method for assembling such a scroll compressor.

Scroll compressors of this kind are known from the Publication of an international application in German translation DE 11 2014 003 869 T5.

Scroll compressors are generally known to one skilled in the art for compressing gases, in particular gaseous refrigerant. They are frequently used as compressors in refrigeration installations in general and in motor vehicle air-conditioning systems, in particular. The basic function thereof is based on the special reciprocal action of two spiral displacers. A spiral displacer is essentially composed of a base plate from which a spiral rib extends upwardly. Two such spiral displacers having correspondingly shaped spiral ribs are positioned opposite one another in a way that allows the spiral ribs thereof to intermesh axially. One of the spiral displacers is thereby housing-fixed. The other spiral displacer executes what is commonly known as an orbiting motion, i.e., it describes a circular motion about the central axis. The compressor space formed between the intermeshing spiral ribs changes periodically in a way that induces gas into the radially outer region of the spiral displacer, conveying it under continuous compression to the spiral center. Located there in the stationary spiral displacer is a pressure relief valve, which extends through the base plate thereof and through which the compressed gas is released into a pressure accumulator chamber. From there, it can be conveyed for application-specific use.

A scroll connector having a three-section housing, which is divided into a two-section outer housing and a one-section inner housing, is known from the above-mentioned generic publication. The outer housing is composed of a motor housing section and a housing cover. The motor housing section is essentially used for accommodating an electric motor designed as an internal-rotor motor having a housing-fixed stator and a rotatable rotor. The rotor is fixed to a main shaft, which is supported at the closed end of the motor housing section in a radial bearing in the form of a floating bearing. The domed housing cover is placed at the open end of the motor housing section and screw fastened thereto. The spiral displacers are placed in the cavity formed by the housing cover. The stationary spiral displacer, which is referred to here as the second spiral displacer, is screw fastened to the housing cover. The orbiting spiral displacer, which is referred to here as the first spiral displacer, is eccentrically coupled to the main shaft that projects beyond the stator. In this area, the main shaft is supported by a second main shaft bearing in a bearing housing section formed as the inner housing in the case of the known scroll compressor. At the same time, the bearing housing section features a guide for the orbiting, first spiral displacer. The bearing housing section is clamped between a mounting flange of the motor housing section and radially outer axial extensions of the stationary spiral displacer. Radially outwardly, it is arched over by the outer wall of the motor housing section, on the one hand, and by the outer wall of the housing cover, on the other hand. The drawback associated with the known scroll displacer is the circumstance that it is only possible in the final assembled state to check the functional performance thereof, which depends, in particular on the precise adjustment and balancing of the mutually relatively movable components thereof. Any necessary readjustment then requires disassembling the entire scroll displacer, resulting in costly additional expenditures.

It is an object of the present invention to provide an improved design for a scroll displacer of the species in a way that will enable the functional performance thereof to be checked already at an early stage of assembly. It is a further object of the present invention to provide a corresponding assembly method.

This objective is achieved in conjunction with the features set forth in the preamble of claim 1 by the second spiral displacer being directly connected to the bearing housing section.

This embodiment makes possible a method for assembling such a scroll compressor, which includes the following steps:

providing a module in a separate process, including the bearing housing section having the preassembled, second main shaft bearing, the preassembled main shaft, and the rotor fixed thereto as well as the preassembled, first spiral displacer and the second spiral displacer directly connected to the bearing housing section, and rotationally driving the main shaft when the bearing housing section is fixed, measuring imbalances, and balancing the module;

providing the motor housing section having the preassembled stator and the preassembled first main shaft bearing and inserting the balanced module into the motor housing section, the main shaft being inserted into the first main shaft bearing, so that the rotor is positioned concentrically within the stator while maintaining an air gap;

screw-fastening the housing cover to the motor housing section, the bearing housing section being sealingly clamped between the motor housing section and the housing cover.

Preferred specific embodiments of the present invention constitute the subject matter of the dependent claims.

In contrast to the related art, the stationary, second spiral displacer is not fixed to the housing cover, but to the bearing housing section. This permits assembly of a module which includes both spiral displacers in the final mutual relative position thereof as well as the main shaft, which is coupled to the orbiting, first spiral displacer and supported in the bearing housing section. This module represents the heart of the scroll displacer, which may be provided in a separate process and checked for the functional performance thereof, in particular for the precise adjustment thereof, independently of remaining components. This may be advantageously accomplished by clamping the bearing housing section in place and by a temporarily connected drive motor rotationally driving the main shaft. Any thereby occurring imbalances may be immediately corrected without requiring any outlay for disassembly, in particular of a housing that impedes access to the components in question. Such a functional test is performed very advantageously, namely in the context of the method of the present invention, where the rotor is already fixed to the main shaft. Alone by the mass thereof, the rotor introduces, namely, a significant potential for imbalance into the system. Therefore, during the manufacture thereof, it is known to provide the rotor with balancing weights which are then removed as needed or reduced by removing material in the course of the functional test explained above. All of this may be accomplished prior to the final assembly on the aforementioned module that is provided in a separate process. Subsequently thereto, the balanced module may then be inserted into the motor housing section provided together with the stator and the first main shaft bearing. If the motor housing section is properly preassembled, the rotor is thereby automatically positioned to rotate coaxially within the stator while maintaining a small air gap. Subsequently thereto, the housing cover may be placed and fixed in position.

The inventive connection between the spiral displacer and the bearing housing section is preferably implemented by screw fastening. It is especially preferred that the screw fastening be realized by a plurality of screws which pass axially through a wall of the bearing housing section and are screwed in place into threaded holes in the second spiral displacer. Thus, in the final assembled state, the screw heads face the motor housing section in this specific embodiment. Therefore, they are not accessible if only the housing cover is removed from a final assembled scroll compressor. However, this is not a disadvantage since the second spiral displacer is connected to the bearing housing section to form the discussed core module already at an early stage of assembly, as described above, and no further change is needed subsequently to adjustment and balancing. In this respect, the preferred orientation of the screws may be regarded as an advantageous measure to avoid inadvertently disassembling the module. A further advantage in the aforementioned orientation also resides in the installation-space conditions, which, in the case of a generally likewise conceivable reverse orientation of the screws would be less favorable.

The preferred embodiment of the present invention provides that the outer wall of the bearing housing section form an axial portion of the wall of the (entire) housing. In other words, the outer housing wall of the final assembled scroll compressor is composed of three axial portions, which are composed of the housing cover, the bearing housing section and the motor housing section (in this order). It would, in fact, also be fundamentally conceivable that the housing cover and/or the motor housing section arch over the bearing housing section radially outwardly in the axial direction, making it possible for the bearing housing section to be in the form of an inner housing, as in the related art. In terms of the radial installation-space conditions, however, this is less favorable than the preferred embodiment of the present invention.

In any case, the bearing housing section is preferably fixed by clamping the bearing housing section between the housing cover and the motor housing section. This may be realized, in particular by the housing cover being fixed by screws which extend axially through the bearing housing section or the outer wall thereof to the motor housing section.

The interfaces between the individual housing sections, i.e., the contact regions between the motor housing section and the bearing housing section, on the one hand, and the bearing housing section and the housing cover, on the other hand, are preferably each sealed by a crimp seal. Even slight manufacturing tolerances may be compensated for by using seals of this type. Moreover, the number of two crimp seals represents an advantageous compromise between ease of assembly, on the one hand, and operational dependability of the seal [(sic.) seals], on the other.

Other features and advantages of the present invention will be apparent from the following special description and drawings,

where:

FIG. 1 shows a sectional view through a scroll compressor according to the present invention in the final assembly state;

FIG. 2 is a sectional view of the scroll compressor of FIG. 1 in a 90° offset sectional plane;

FIG. 3 is a sectional view of the core module of the scroll compressor of FIGS. 1 and 2.

Identical reference numerals in the figures indicate the same or analogous elements.

In a 90° offset sectional view, FIGS. 1 and 2 show a scroll compressor 10 according to the present invention. The housing of scroll compressor 10 is composed of three housing sections, namely a motor housing section 12, a bearing housing section 14 and a housing cover 16. As is apparent from FIG. 2, the mentioned housing sections are fixed to one another by long screws 18 in the embodiment shown. Long screws 18 thereby extend through the outer walls of housing cover 16 and of bearing housing section and are screwed into the corresponding thread in motor housing section 12. In this manner, bearing housing section 14 is clampingly held between motor housing section 12 and housing cover 16. In a manner not shown in greater detail, the interfaces between the individual housing sections are each sealed by a crimp seal.

Positioned within motor housing section 12 is an electric motor, whose stator 20 is housing-fixed, and whose rotor 22 is fixed on a concentrically mounted main shaft 24, so that it is pivotally mounted within stator 20. The mounting support of main shaft 24 in motor housing section 12 is implemented by a first main shaft bearing 26, which is provided as a floating bearing at the closed side (on the left in FIGS. 1 and 2) of motor housing section 12. A second main shaft bearing 28 is provided in bearing housing section 14, into which main shaft 24 extends.

At the front end thereof, main shaft 24 has an eccentric coupling 30 having an orbiting, first spiral displacer 32. To ensure an orbiting motion during rotation of main shaft 24, first spiral displacer 32 is guided in corresponding guides 34 in bearing housing section 14, and spiral rib thereof extends axially into the spiral rib of a stationary, second spiral displacer 36. Second spiral displacer 36 is directly connected by short screws 38 to bearing housing section 14.

This results in the option of preassembling a module 100, which forms the principal part of the scroll connector and is shown separately in FIG. 3. All essential adjustment and balancing work may be performed in a separate process on this module 100. Adjusted and balanced module 100 may then be inserted into motor housing section 12, which is preassembled to include stator 20 and first main shaft bearing 26, and, following placement of housing cover 16, fixed by long screws 18. In the illustrated specific embodiment, housing cover 16, as an essential functional unit, accommodates merely pressure accumulator chamber 40 into which the gas compressed between spiral displacers 32, 36 is conveyed.

It is self-evident that the specific embodiments discussed in the special description and shown in the figures only represent illustrative exemplary embodiments of the present invention. In light of the present disclosure, a broad spectrum of possible variations is made available to one skilled in the art. In particular, it is also conceivable to configure bearing housing section 14 as an inner housing that is arched over radially outwardly in the axial direction by motor housing section 12 and/or by housing cover 16, which then abut directly against one another. In this embodiment, it is possible to dispense with an interface to be sealed between the housing sections. On the other hand, in terms of the radial installation space, this variant is less favorable than that shown in FIGS. 1-3.

LIST OF REFERENCE NUMERALS

10 scroll compressor

12 motor housing section

14 bearing housing section

16 housing cover

18 long screw

20 stator

22 rotor

24 main shaft

26 first main shaft bearing

28 second main shaft bearing

30 eccentric coupling

32 first spiral displacer

34 guide

36 second spiral displacer

38 short screw

40 pressure accumulator chamber 

1. A scroll compressor having a housing composed of a plurality of housing sections, comprising a motor housing section in which is configured a drive motor having a housing-fixed stator and a coaxial rotor fixed to a main shaft mounted on one side of the stator by a first main shaft bearing; a bearing housing section, which adjoins the motor housing section on the side facing away from the first main shaft bearing and which supports a second main shaft bearing as well as an orbital guide of a first spiral displacer, which is eccentrically coupled to the main shaft and orbits in response to the rotation thereof, and into which axially engages a housing-fixed, second spiral displacer; a housing cover which adjoins the bearing housing section and terminates the housing, wherein the second spiral displacer is directly connected to the bearing housing section.
 2. The scroll compressor as recited in claim 1, wherein the second spiral displacer is screw fastened to the bearing housing section.
 3. The scroll compressor as recited in claim 2, wherein the screw fastening is realized by a plurality of screws which extend axially through a wall of the bearing housing section and are screwed in place into threaded holes in the second spiral displacer.
 4. The scroll compressor as recited in claim 1, wherein the outer wall of the bearing housing section forms an axial portion of the outer wall of the housing.
 5. The scroll compressor as recited in claim 1, wherein the housing cover is fixed to the motor housing section by the bearing housing section or by screws which extend axially through the outer wall thereof.
 6. The scroll compressor as recited in claim 1, wherein the contact regions between the motor housing section and the bearing housing section, on the one hand, and between the bearing housing section and the housing cover, on the other hand, are each sealed by a crimp seal.
 7. A method for assembling a scroll compressor according to claim 1, comprising the steps of: providing a module in a separate process, including the bearing housing section having the preassembled, second main shaft bearing (28), the preassembled main shaft, and the rotor fixed thereto as well as the preassembled, first spiral displacer and the second spiral displacer directly connected to the bearing housing section, and rotationally driving the main shaft when the bearing housing section is fixed, measuring imbalances and balancing the module; providing the motor housing section having the preassembled stator and the preassembled first main shaft bearing and inserting the balanced module into the motor housing section, the main shaft being inserted into the first main shaft bearing, so that the rotor is positioned concentrically within the stator while maintaining an air gap; screw-fastening the housing cover to the motor housing section, the bearing housing section being sealingly clamped between the motor housing section and the housing cover.
 8. The method as recited in claim 6, wherein the module is balanced by removing rotor-fixed balancing weights or by removing material therefrom. 